Are these bags machine washable? I've had mine for a couple of years and they are in need of a thorough cleaning. If I put it in the washer, will it remain waterproof?

Tech Specs:

Material:

210D nylon; [buckle] Duraflex 

Dimensions:

[5 L] 10 x 20 in; [15 L] 14 x 28 in; [25 L] 16 x 33 in; [50 L] 20 x 40 in 

Volume:

5 L, 15 L, 25 L, 50 L 

Backpack Straps:

no 

Closure:

roll-top 

Weight:

(5L) 204 g, (15L) 368 g, (25L) 476 g, (50L) 697 g 

Recommended Use:

water sports 

Manufacturer Warranty:

lifetime